The present invention relates to a barcode scanner, and more particularly to a pen-type barcode scanner which features energy saving while increasing the performance.
The barcode has been widely and intensively used in merchandise It classifications, inventory management because it can be readily recognized, a great deal of diversity. In addition, the barcode can be readily processed by electronic equipments. A plurality of barcode scanners has been marketed to meet different usage. For example, a platform barcode scanner is widely used in the supermarket for checkout of different merchandises, while a pen-type barcode scanner is used to read barcode carried on a label.
Referring to FIGS. 1 and 2A, a conventional pen-type barcode scanner 1 includes a cylindrical housing 10 having a signal cable 2 connected at an end thereof. The cylindrical housing 10 further includes an approaching end 101 in which a convex lens and an aperture are defined. The cylindrical housing 10 is incorporated with a scanning assembly 11 including a plastic member 111 having a central passage 112 defined therein. The plastic member 111 is further provided with a light source 113, a focusing device 114, a signal receiving/converting device 115 and a printed circuit board 116. The light source 113 is configured by a plurality of LED symmetrically arranged on an end surface of the plastic member 111.
When a barcode is to be scanned, the light source 113 is switched and provides an emitted light beam passing through the lens (aperture) of the approaching end 101 of the cylindrical housing 10. A reflected light beam from the barcode is then picked up through the lens (aperture) of the approaching end 101. The reflected light beam is firstly focused by the focusing device 114, and then transferred to the signal receiving/converting device 115 after the light beam is enhanced by the focusing device 114. The reflected light beam is converted into an electrical signal by the printed circuit board 116 together with the receiving/converting device 115. Then a processed signal can be transmitted to other electronic device for further processing.
However, the conventional pen-type barcode scanner encounters a light diffusion on the projected light beam. Not only will the reflected light beam be negatively influenced, but will also exhaust more energy.
The main defect of the conventional barcode scanner is that the light intensity of the light source, i.e. the LED, is not strong enough such that the intensity of the reflected light beam is too weak to be decoded by the receiving/converting device 115. As a result, the information contained within the reflected light beam from the barcode can not be accurately retrieved. Accordingly, in order to compensate this insufficient intensity, the power supplied to the LED should be increased and more energy is exhausted.
The other reason for why the conventional barcode scanner can not get a strong reflected light beam is because of the arrangement of the LED 113. As shown in FIG. 2A, the LEDs 113 are arranged on the front end surface of the plastic member 111 and which are located in the front of the focusing device 114. As a result, when light beams projected from the LEDs 113 have a comparable larger inlet angle xcex8 which inevitably creates light diffusion. Consequently, the intensity of the light beams projected toward the barcode is accordingly attenuated. On the other hand, the LEDs 113 are distant to the aperture (lens) of the approaching end 101. As a result, the light beams can reach thereof after a plurality of reflections which will also attenuate the intensity of the light beams. Again, in order to compensate this defect, the power and number of the LEDs 113 have to be increased and which inevitably increase the cost of the barcode scanner. As clearly shown in FIG. 2B, there are four LEDs used in the conventional barcode scanner. Not only will increase the complexity of the overall structure, but will also increase the cost. As such, there is still a room to provide an improved barcode scanner to meet the market requirement.
An object of this invention is to provide a pen-type barcode scanner which features a reduced light travel path between a light source device and a barcode to be read. The emitted light beam can profoundly be projected onto the barcode via a reduced inlet angle thereby benefiting enhanced reflected light. Accordingly, the decoding of the barcode can be readily performed.
According to one aspect of the present invention, the light source device is a single LED device thereby simplifying the overall structure of the barcode scanner.
In order to achieve the objects set forth, a barcode scanner for reading barcode image carried by an object in accordance with the present invention comprises a cylindrical housing having a barcode approaching end and an output end opposite to the approaching end, and a scanning apparatus located within the housing.
The scanning apparatus includes a focusing device, a light source device, a signal receiving/converting device, and a printed circuit board carrying the devices. The focusing device is located in a central line passing a center of an aperture located in the approaching end and on while a lens is seated.
According to one of the aspects of the present invention, the light source device is located to a central line and is more closer to the barcode thereby the projected light beam can be projected toward the barcode along a reduced inlet angle. Consequently, light diffusion and loss can be largely reduced thereby providing an enhanced reflected light. The accuracy and performance can therefore increased.
According to another aspect of the present invention, the scanning performance is largely increased by approaching the light source device to the barcode to be scanned thereby simplifying the overall structure. As a result, the barcode scanner in accordance with the present invention can be easily manufactured.